This invention relates to a capacitor discharge ignition system which operates in a ferroresonant mode. The ignition system may be used for a spark-ignition internal combustion engine of the reciprocating or rotary type.
The term "ferroresonant ignition system" , as used herein, refers to an ignition system that utilizes an ignition coil having primary and secondary windings wound on a ferromagnetic core. The secondary winding of the ignition coil is coupled to a capacitor connected in series with a spark gap. The voltage across this capacitor and the current flow through the spark gap oscillate at a frequency f defined by the expression: EQU f = V.sub.m /4N.sub.s .phi..sub.s
Where V.sub.m is the maximum voltage across the capacitor, N.sub.s is the number of turns in the secondary winding, and .phi..sub.s is the magnetic flux within the secondary winding at magnetic saturation of the ferromagnetic core of the ignition coil.